This project proposes to investigate the relation of platelet morphology to the pathogenesis of complications in certain chronic and acute disease states in which platelet function and morphology has been reported abnormal. Further, the project will explore means acting upon cellular function by which acutely induced thrombotic and nonthrombotic myocardial injury can be limited and myocardial viability and function preserved. Diagnostically the project will explore the development of biochemical methods enabling the detection of thrombotic state utilizing radioisotopically labelled tracers. In addition work will continue on radioisotopic imaging of thrombus and ischemic myocardium resulting from coronary occlusion of venous etiology. The entire project will be carried out on experimental animals in which a controlled condition will be induced and followed by sequential acute or chronic observations relevant to the above described objectives.